The present invention relates to a container intended to sustain an internal pressure and which can be disassembled into two elements, a first element having a cylindrical portion which penetrates into a cylindrical portion of a second element, the container also including a seal inserted between these two cylindrical portions.
When the joining line of the two elements of a two-part pressure-resistant container has a considerable length, recourse is often had to a connection via parallel flanges between which is placed a seal. This arrangement is reliable but heavy and unwieldy, and the operations of assembling and disassembling the container are lengthy. This is in particular the case when the container, which is for example cylindrical with two optionally convex ends, includes two elements joined in the portion of maximum diameter, i.e., in order to facilitate inspection and cleaning operations. At least one of the two elements can have closable orifices of a smaller diameter for filling or emptying, and the closing of these orifices generally presents less serious problems.
The disassemblable containers which make use of the penetration of a cylindrical portion (male portion) into another portion (female portion) are less heavy and less unwieldy by virtue of the absence of the flanges. In particular, they have the advantage of permitting rapid assembly and disassembly. However, they have the risk, which is inherent to rapid disassembly, of this disassembly taking place whilst the container is still pressurized, which can cause accidents.
In order to avoid this risk, it has been proposed in European Patent Application No. 0,325,518 to provide for the outer surface of the female element to bear fastening means capable of interacting with fastening means provided on a connecting member integral in axial translational motion with the male element, and for the thickness of the female element to be calculated so that when a specified internal pressure is applied to the container, the latter deforms in order to make it impossible for the fastening means to be actuated with a view to opening the container. This advantageous solution requires that the operating pressure and the deformability properties of the material are known and remain within specified limits.
Also, U.S. Pat. Nos. 3,990,605 and 4,444,331 disclose a locking device connected to a device for connection to the atmosphere. In both cases there is a valve for connection to the atmosphere, the outer part of which forms a cap and can be removed by being unscrewed. When this outer part is screwed in, it prevents the lid from being unscrewed by virtue of a lug or a fork which is connected to the lid, and abuts this outer part. This piece therefore must be unscrewed in order to be able to turn the lid, which results in the container being connected to the atmosphere.
These devices make use of a disassemblable piece which must be removed each time the container is opened. It is possible for this piece to be replaced by a replacement closing means, devised by the user, and which does not fulfill the safety function in an appropriate manner. This can be because the disassemblable piece is damaged or because the user wishes to avoid having to carry out the disassembly each time he opens the container.
Furthermore, U.S. Pat. No. 4,620,643 and German Patent Application 1,297,424 disclose locking devices associated with a means for connection to the atmosphere. A valve for connection to the atmosphere comprises a movable piece connected to a shutter, and a movable locking member comprises a surface which is displaced perpendicularly to the axis of the shutter and comprises a cavity capable of receiving the movable piece. When the movable piece penetrates into the cavity, the shutter closes, permitting the pressurization, and simultaneously the locking member is immobilized by the movable piece in a position locking the lid. When a different portion of the movable surface is opposite the movable piece, the shutter is held open, and at the same time the locking member can be displaced.
The presence of this locking member gives rise to a complication, and hence an increase in costs.